Originally Posted by scott page

Absolutely correct about moisture! Water is a very effective block of 2.4 radiation -- well.. it absorbs it -- which is why your microwave -- which uses 2.4ghz -- makes a cup of water so hot. You will see reduced range in heavy fog, mist, rain, even very high humidity. Also, keep the antenna dry and not blocked by anything that would get hot in a microwave oven.

High Humidity? damn, have you ever been in Sout Florida during the summer?
100% humidity is not uncommon...its muggy and miserable down here during the summer.

So after all these years I finally joined the ranks of a 2.4 user. I chose the FrSky system after reading some reviews and received the module for my Futaba 10C, 2 D6FR's and a V8R4 for Christmas...I then ordered the rest of the V8R4's that Aloft had in stock and got a couple more D6FA's. I only have a dozen flights on the FrSky system but so far so good.

I impetus to jump on the 2.4 wagon was that I was having some severe range/glitching issues with some of my 72mhz stuff, not sure why as the Tx was checked over by Futaba a few weeks ago and came back with a clean bill of health. In both my Stevens Aero Edge, Laser-E (Old F5B plane) and even on my little GWS Moth I got severe glitching (scary on the Edge and Laser) even after changing out Rx's and my moth had a range of about 500'. So far I have flown my Guru-Z heli (which had slight glitching) the Moth and my Techone Venus and no issues at all

I do have one question....do other people have an issue with the module fitting in the receiver of there Futaba Tx? Mine is a VERY tight fit.

Cheers,
Jim

Mine is a tight fit in both of my 9ZAPs but I don't consider that an issue.

In 9C no, it fits perfectly to be replaced very frequent, 3-4 times per flight session, and not develop any play, yet.
Replacement occurs between multiple Frsky modules, is my "Model Match" way.

Originally Posted by u2builder

The other day I was getting ready to fly my multicopter. I have the 2 way module in my Futaba 9C and a D8R-XP reflashed with DAC RSSI attached.
As I was waiting for the GPS to lock on the RX suddenly lost signal (red light blinking) and the quad went into failsafe (sitting on the ground, motors not armed).

I aborted the mission and took it in and put it on the bench. I am not sure whether it regained the signal immediately when I powered the machine or whether it took a second repowering, but I did not have to rebind it.

I have done a couple flights since but I am a bit nervous.

Thanks.

Well, it happened again, this time during a flight. I was flying FPV. I was monitoring RSSI on my Goggles which was reading 3.7 (max about 4.2, min about 2.3 during range check mode). I was maybe 200 meters out and 20 meters high. All of a sudden the quad went into Failsafe mode. It returned home and autolanded, amazingly in the exactly same spot in the 3 meter wide spot in the packed down snow where I took off from.

When my nerves settled I notice that the receiver had a blinking red light rather than the solid light. In other words it had not regained a signal even when it was right in front of me.

I repowered it twice outdoors and it did not go to solid red indicating a signal. I tried turning off the TX before the second repower. I then brought it indoors and repowered it and it went to solid red. I watched it for about 20 minutes while flipping switches on the TX and it stayed red indicating it had a signal. The RSSI also indicated it had full signal.

So, here's the summary. The first time it lost its bind sitting on the ground. I thought maybe the antenna or radio on the ground might have been the problem. The second time it lost it flying when it should have been well within range. In both cases it required a couple or more repowering of the RX after which it bound fine and appear to work for many more minutes than the time of either failure. I also had a couple of sucessful flights inbetween.

I figure it must be the TX module or the RX module or some problem between the DAC and the RX module. What else could it be at this point.

Which is it most likely to be? Any suggestions appreciate. Intermittant problems are very hard to figure out.

Any "experiments" I should consider?

I don't know but, how cold is it there? worth testing?

Well, it isn't that cold, relatively speaking. Probably about 32F (0C) both times that this happened. But I guess it is worth testing. But "after" it happen I put it outdoors for about 15 minutes with the copter plugged in and the RX on and didn't lose signal. Since then I've left it on indoors for probably another 30 minutes and didn't lose signal. This is really wierd.

I don't know but, how cold is it there? worth testing?

OK, it is the cold. I just put the radio and the quad outdoors at 25F for a few minutes and the D8R-XP lost signal. I brought the radio in and the signal was not regained. I then brought the quad in, leaving everything still "on" and after it warmed up for a few minutes it regained the signal. I repeated the experiment this time with the radio indoors and the quad outdoors. After a few minutes it lost signal. It reagained signal a few minutes after I brought it in.

This is consistant with both of my failures in the field reported above. Both times it was around or just below freezing and both times the RX lost signal after a minutes outdoors, once on the ground and once flying. In both cases it reagained signal when I tested it on my bench a few minutes later.

So my D8R-XP does not operate properly in cold weather. The question: Is this a problem with D8R-XP in general or just mine?

I just put my hex outdoors at about 25 degrees F. It is fitted with a
Frsky D8R-II Plus. Unlike my D8R-XP, which was reflashed and had the RSSI DAC attached, it is factory stock, has never been reflashed, and does not have the RSSI DAC converted attached. After about 10 minutes outdoors, more or less, the RX lost signal. I brought the hex indoors and it regained signal in a few minutes.

So both my Frsky D8R-XP and D8R-II Plus RX's appear to lose signal when it is cold out, even though the radio is near them, either outdoors, or indoors on the other side of the door. The signal strength is near max as evidenced by the RSSI on the DAC converter right up to the time it is lost completely.

This is a MAJOR BUMMER. I was really hoping to do some serious flying this long winter.

I guess I will need to look into creating some type of heated enclosure for my RX's. This is a very unforgiving hobby.

Originally Posted by u2builder

I just put my hex outdoors at about 25 degrees F. It is fitted with a
Frsky D8R-II Plus. Unlike my D8R-XP, which was reflashed and had the RSSI DAC attached, it is factory stock, has never been reflashed, and does not have the RSSI DAC converted attached. After about 10 minutes outdoors, more or less, the RX lost signal. I brought the hex indoors and it regained signal in a few minutes.

So both my Frsky D8R-XP and D8R-II Plus RX's appear to lose signal when it is cold out, even though the radio is near them, either outdoors, or indoors on the other side of the door. The signal strength is near max as evidenced by the RSSI on the DAC converter right up to the time it is lost completely.

This is a MAJOR BUMMER. I was really hoping to do some serious flying this long winter.

I guess I will need to look into creating some type of heated enclosure for my RX's. This is a very unforgiving hobby.

This and a rubber band is the answer to your troubles!-

Originally Posted by goldsworthy

This and a rubber band is the answer to your troubles!-

Yeah, I was actually thinking of a handwarmer. I have also been thinking of an insulated box. Gonna have to do something.

Originally Posted by u2builder

OK, it is the cold. I just put the radio and the quad outdoors at 25F for a few minutes and the D8R-XP lost signal. I brought the radio in and the signal was not regained. I then brought the quad in, leaving everything still "on" and after it warmed up for a few minutes it regained the signal. I repeated the experiment this time with the radio indoors and the quad outdoors. After a few minutes it lost signal. It reagained signal a few minutes after I brought it in.

This is consistant with both of my failures in the field reported above. Both times it was around or just below freezing and both times the RX lost signal after a minutes outdoors, once on the ground and once flying. In both cases it reagained signal when I tested it on my bench a few minutes later.

So my D8R-XP does not operate properly in cold weather. The question: Is this a problem with D8R-XP in general or just mine?

Have you checked your battery/power system yet? Normally Rx can work until -20℃ (-4F). Batteries are also can be effected by the temperature, some of them are even more sensitive than receivers.

If your battery is "weaken" by cold, your Rx will be effected (by low voltage).

Originally Posted by Zeeland

Have you checked your battery/power system yet? Normally Rx can work until -20℃ (-4F). Batteries are also can be effected by the temperature, some of them are even more sensitive than receivers.

If your battery is "weaken" by cold, your Rx will be effected (by low voltage).

My thoughts as well, try putting only the battery outside.

But if it does turn out to be the receiver failing at this temperature I would not risk using it. And FrSky would have some "splainin" to do.

Originally Posted by u2builder

I just put my hex outdoors at about 25 degrees F. It is fitted with a
Frsky D8R-II Plus. Unlike my D8R-XP, which was reflashed and had the RSSI DAC attached, it is factory stock, has never been reflashed, and does not have the RSSI DAC converted attached. After about 10 minutes outdoors, more or less, the RX lost signal. I brought the hex indoors and it regained signal in a few minutes.

So both my Frsky D8R-XP and D8R-II Plus RX's appear to lose signal when it is cold out, even though the radio is near them, either outdoors, or indoors on the other side of the door. The signal strength is near max as evidenced by the RSSI on the DAC converter right up to the time it is lost completely.

This is a MAJOR BUMMER. I was really hoping to do some serious flying this long winter.

I guess I will need to look into creating some type of heated enclosure for my RX's. This is a very unforgiving hobby.

The Rx should be able to handle that temp. LiPo's have to be kept warm until you use them then the currant going through them is usually enough to kept them warm enough to work. Running just the Rx is not enough currant to keep the LiPo's warm enough. Maybe some electrical interference from one of your componants is causing your problem. I would think it is highly unlikely to have2 bad RX's.

The Rx should be able to handle that temp. LiPo's have to be kept warm until you use them then the currant going through them is usually enough to kept them warm enough to work. Running just the Rx is not enough currant to keep the LiPo's warm enough. Maybe some electrical interference from one of your componants is causing your problem. I would think it is highly unlikely to have2 bad RX's.

I don't think it is electrical interference. This happens with two different machines with different equipment. It doesn't happen indoors or when it is warm out. The hex has flown quite a few flights with the present RX during warmer weather.

I also don't think it is the LIPOs. I was reading about 11.3 volts on my OSD when the the quad went into failsafe during flight and the machine had plenty of voltage to ascend to 20 meters, hover, come home, hover and auto land. The signal did not come back on (until I brought the machine indoors into the shop where it was warmer). The batteries were at about 60 percent capacity when I checked them. But I can experiment with this to make sure.

I have another D8R-XP as well as a V8R7SP. I'll just put a fresh NiMh RX battery wrapped in a handwarmer and take them outdoors in the cold. There will be no other equipment to cause interference. It should be interesting.